According to police's initial findings, on August 12, Tien had 14 Recotus pills after coming back from a wedding party, because his mother refused to give him money to buy drugs.

He consumed the drugs on the side of a ditch in Phan Ri Cua Town, where he lives, the An ninh thu do (Capital security) news website quoted police as saying, adding that he had nine knives with him.

He then went on a rampage, attacking people in nearby houses and on the street, including children and disabled people, the report said.

One of his victims died in the hospital later the same day. Eighteen of the 20 injured people have been discharged, it said.

It quoted Tien as telling police that he had used drugs for more than ten years and had been sent to rehab centers two times, but he had failed to kick his habit. Recently he had switched to Recotus because he could not afford drugs.

Tien was prone to violence after taking drugs, the news website reported, adding that ten days before his rampage, he had slashed and injured another man.

In the meantime, Diep Dinh Khoi, the secretary of the Party Unit at Phan Ri Cua Town, told Thanh Nien that Tien's family had previously chained him in an effort to stop him from using drugs and attacking people, but things were still the same after he was released.

Khoi said local authorities do pay attention to supervising drug addicts but are not effective all the time.

In fact, one of the provincial hot spots of drug crimes with 177 addicts and 225 others suspected of using drugs, Phan Ri Cua is facing the risk of "security disorders", Captain Nguyen Trong Dong, deputy chief of the town's police, told Thanh Nien.

He said people started using drugs on returning home after being at sea, fishing, for more than two months.

At first they used marijuana and ate well, slept well and gained weight, but later they switched to synthetic drugs as marijuana no longer satisfied them, Dong said.

In the first half of the year, local police arrested 19 people when busting 17 cases of drug trade and storage, Dong said.

Towards the end of last year, several media reports said that many students in Ho Chi Minh City used Recotus, believing that it could help keep them awake, feel happy and boost their confidence. Some students said they used the medicine to pretend to be sick in order to skip classes, as it could make them tired.

Health experts then warned that the abuse of the medicine, which was produced by a HCMC-based pharmaceutical company and could be bought without doctors' prescriptions, was as dangerous as drug use.

While it could intoxicate, if abused, it could increase heart beat and blood pressure to dangerous levels, they said.